(MCT) — WEST PALM BEACH, Fla. — FBI agents on Wednesday removed dozens of boxes from the office of an eye doctor and Democratic donor with close ties to new Senate Foreign Relations chairman Robert Menendez, D-N.J.

Menendez denied allegations that he had sex with underage prostitutes while visiting a home of the donor, Dr. Salomon Melgen, in the Dominican Republic. It was not clear if the raid on Melgen’s office was related to Menendez.

Agents arrived Melgen’s Vitreo-Retinal Consultants Eye Center on Tuesday night and on Wednesday afternoon loaded at least 63 cardboard boxes onto vans. Personnel from the Office of the Inspector General for the federal Department of Health and Human Services were also on hand.

An FBI spokesman on the scene said agents were “conducting law enforcement action at this location” but would not comment further.

Efforts to reach Melgen were unsuccessful.

The conservative Daily Caller website has published allegations that Menendez flew to the Dominican Republic on Melgen’s private plane and had sex with underage prostitutes there while visiting a home owned by Melgen. The website last week published copies of what appeared to be FBI e-mails confirming the agency had begun investigating the prostitution claims in August.

Menendez told the Daily Caller this week that the prostitution allegations are “fallacious.”

The nonpartisan Citizens for Responsibility and Ethics in Washington revealed Wednesday that it asked the Justice Department and the FBI’s Washington field office in July to investigate allegations that Menendez had engaged in “illicit sexual acts with underage prostitutes” while visiting Melgen’s home in the Dominican Republic.

CREW, the group that helped bring down former Palm Beach County Rep. Mark Foley in a 2006 Internet sex scandal, said it asked federal authorities to investigate Menendez after being unable to independently verify the truth of the allegations.

Menendez’s office on Wednesday described Melgen as a “friend and political supporter” of the senator but denied any wrongdoing by Menendez.

“Sen. Menendez has traveled on Dr. Melgen’s plane on three occasions, all of which have been paid for and reported appropriately. Any allegations of engaging with prostitutes are manufactured by a politically motivated right-wing blog and are false,” said the statement.

Melgen, 58, lives in a home appraised at $2.1 million in Captain’s Landing near North Palm Beach. He has offices in West Palm Beach, Wellington, Port St. Lucie and west of Delray Beach.

On Wednesday, the West Palm Beach office was behind yellow crime-scene tape while a locksmith and workers with drills and crowbar were seen entering the building.

The Wellington office, which Melgen shares with another doctor, was open on Wednesday. Employees there said Melgen was not in and they knew nothing of the FBI’s activities beyond what they had seen on television.

At Melgen’s Delray Beach office, a hand-lettered sign said “Office Closed — Call to Reschedule.” That office and the one in Port St. Lucie were also raided by the FBI, The Miami Herald reported.

Melgen, who was born and raised in the Dominican Republic, also is chairman and founder of Voxxi, an online news an online news site catering to Hispanics in the United States.

Court records show an outstanding lien of $11.1 million against Melgen from the Internal Revenue Service. A previous IRS lien for $6.2 million was released in 2011.

Melgen, his family members and his businesses have contributed more than $450,000 to state and federal candidates since the early 1990s, according to federal and state records. More than 90 percent of the money has gone to Democrats, including Florida Sen. Bill Nelson and current and former Democratic Reps. Debbie Wasserman Schultz, Ron Klein, Tim Mahoney and Alcee Hastings.

Klein, who received contributions from Melgen for his state legislative and congressional campaigns, said he does not know Melgen well. He said he met the eye doctor through former Gov. Lawton Chiles in the early 1990s and that Melgen had an interest in health care reform. Melgen performed eye surgery on Chiles in 1997.

During Menendez’s 2012 re-election bid, Melgen family members gave $15,000 to Menendez’s campaign, $30,000 to the New Jersey Democratic Party and $60,400 to the Democratic Senatorial Campaign Committee.

Menendez became chairman of the Senate Foreign Relations Committee on Tuesday, when the former chairman, John Kerry, was confirmed as secretary of State.

Menendez and Republican Sen. Marco Rubio of Florida have also been in the headlines recently as members of a bipartisan “Gang of 8” senators supporting immigration reform.

While Menendez’s office said the senator paid for and reported his trips on Melgen’s plane, the Associated Press reported that it searched six years of office and travel-related expenses for Menendez’s U.S. Senate office and found no reports reflecting payments to Melgen or trips aboard Melgen’s plane.

The AP also found no apparent reimbursement to Melgen in more than six years’ worth of campaign expenses on file with the Federal Election Commission.